DPP: Take response wait time into account for init retries

Previously, the Authentication Request frame was retried after 2+10 = 12
seconds since the wait for the response was not accounted for. Substract
that wait from the 10 second wait time to start the retries more quickly
based on the 10 second timer described in the tech spec.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/dpp_supplicant.c

@@ -657,7 +657,8 @@ static int wpas_dpp_auth_init_next(struct wpa_supplicant *wpa_s)
 {
 	struct dpp_authentication *auth = wpa_s->dpp_auth;
 	const u8 *dst;
-	unsigned int wait_time, freq, max_tries;
+	unsigned int wait_time, freq, max_tries, used;
+	struct os_reltime now, diff;
 
 	if (!auth)
 		return -1;
@@ -684,6 +685,15 @@ static int wpas_dpp_auth_init_next(struct wpa_supplicant *wpa_s)
 			wait_time = wpa_s->dpp_init_retry_time;
 		else
 			wait_time = 10000;
+		os_get_reltime(&now);
+		os_reltime_sub(&now, &wpa_s->dpp_last_init, &diff);
+		used = diff.sec * 1000 + diff.usec / 1000;
+		if (used > wait_time)
+			wait_time = 0;
+		else
+			wait_time -= used;
+		wpa_printf(MSG_DEBUG, "DPP: Next init attempt in %u ms",
+			   wait_time);
 		eloop_register_timeout(wait_time / 1000,
 				       (wait_time % 1000) * 1000,
 				       wpas_dpp_init_timeout, wpa_s,